Embedded NMR sensors to monitor evaporable water loss caused by hydration and drying in Portland cement mortar

• Published in: Cement and concrete research 2009-04, Vol.39 (4), p.324-328
• Main Authors: de J. Cano-Barrita, P.F., Marble, A.E., Balcom, B.J., García, J.C., Masthikin, I.V., Thomas, M.D.A., Bremner, T.W.
• Format: Article
• Language: English
• Subjects: A: Drying; Applied sciences; B: Pore size distribution; Buildings. Public works; Cement concrete constituents; Cements; Concretes. Mortars. Grouts; E: Mortar; Embedded NMR sensor; Exact sciences and technology; General (composition, classification, performance, standards, patents, etc.); Hydration; Materials; Measurements. Technique of testing; Properties of anhydrous and hydrated cement, test methods
• ISSN: 0008-8846; 1873-3948
• DOI: 10.1016/j.cemconres.2009.01.011

Providing adequate moisture content in cement-based materials is important during hydration of the cement paste to ensure proper development of their mechanical and durability properties. Subsequently, water is involved in the deterioration of concrete either as a pure liquid or by carrying aggressive species. This paper explores the use of small embedded NMR sensors to monitor evaporable water loss in Portland cement mortars. Results indicate that these sensors are effective in detecting loss of evaporable water due to hydration and drying. During drying, the mass loss is linearly proportional to the NMR signal loss. In addition, the amount of evaporable water detected with the sensor has a good correlation with the amount of evaporable water in a companion specimen tested in a traditional low field magnet by NMR and by gravimetric measurements.